Why Your Heat Pump Runs But Doesn’t Heat Your Home

If your heat pump is running but your home still feels cold, you're not alone. This is a common concern among homeowners throughout Hillsboro and the surrounding areas, especially during chilly Oregon mornings. A heat pump that appears to be working—but fails to deliver warm air—can leave you uncomfortable and frustrated.

At Aviator Heating & Cooling, we specialize in identifying and fixing these exact problems. Below, we’ll explain why this happens, what warning signs to look for, and how professional heat pump repair or replacement can restore reliable comfort to your home.

Common Reasons Your Heat Pump Isn’t Heating

It’s one of the most frustrating winter problems: your heat pump is running, yet your home still feels cold. While the unit may sound like it’s working, there are several mechanical, environmental, or system-related issues that can prevent it from delivering heat effectively.

At Aviator Heating & Cooling, we’ve helped homeowners across Hillsboro, Forest Grove, Beaverton, and beyond solve these exact problems. Below are the most common causes we see—and how we resolve them.

1. The System Is in Cooling Mode by Mistake

This might sound simple, but it’s surprisingly common. A quick thermostat setting change, power outage, or even a software bug in a smart thermostat can result in the system staying in “cool” mode.

Why it matters:
If your system is cooling instead of heating, it may actually draw heat out of the home on cold days—making your comfort problem worse.

Solution:
Double-check that your thermostat is set to "heat" and that the target temperature is above the current room temperature. If the display is blank, flickering, or unresponsive, you may have a thermostat malfunction. We offer smart thermostat installation and calibration services to ensure accurate control and prevent similar issues in the future.

2. Outdoor Unit Is Frozen Over

It’s normal for frost to form on your outdoor unit during colder months, but it should automatically defrost every so often. If it doesn’t, ice can accumulate to the point where the system can’t pull heat from the outside air—a problem especially common in Oregon’s damp winters.

Common causes:

• • • Defrost sensor or timer malfunction
    • Obstructed airflow due to overgrown shrubs, leaves, or dirty coils
    • Low refrigerant preventing heat transfer
    • Faulty wiring or control board errors

Solution:
If the unit is encased in ice, turn it off and avoid scraping or damaging it further. Our technicians provide comprehensive heat pump diagnostics throughout Hillsboro, Tigard, and Aloha, and we can quickly resolve defrost cycle problems, clean the outdoor unit, and restore safe operation.

3. Low Refrigerant Levels or Refrigerant Leak

Refrigerant is the substance that moves heat between the indoor and outdoor units. Without enough refrigerant, your heat pump might run non-stop but fail to warm your home—especially during colder stretches.

Warning signs include:

• • • Cool or room-temperature air from vents
    • Ice buildup on indoor or outdoor coils
    • Unusual noises, like hissing near the refrigerant line
    • Higher energy usage without improved comfort

Solution:
Only certified HVAC technicians can legally handle refrigerant. At Aviator Heating & Cooling, we offer leak detection, pressure testing, and recharge services, ensuring your system is properly sealed and operating efficiently.

4. Dirty Filters or Blocked Airflow

Clogged air filters and blocked return vents are a silent killer of system performance. Poor airflow causes your heat pump to work harder than necessary, often running longer while still failing to adequately heat the home.

What to watch for:

• • • Inconsistent temperatures in different rooms
    • Dust accumulation near vents
    • A noticeable drop in airflow or longer cycles

Solution:
Replace filters every 1 to 3 months during heavy-use seasons. Our HVAC maintenance services include thorough filter replacement, indoor coil cleaning, and static pressure testing to ensure unrestricted airflow throughout your duct system.

5. Reversing Valve Failure

Your heat pump relies on a reversing valve to switch between heating and cooling. If this valve sticks or fails, the system may stay in cooling mode even when you’ve set it to heat. This can leave the blower running but produce cold or neutral air indoors.

What we see locally:
This is a common issue in older systems, especially those that haven’t had seasonal tune-ups. Power surges, wear, or internal component failure can all cause valve malfunction.

Solution:
We regularly perform reversing valve repairs and replacements for customers in Forest Grove, North Plains, and Hillsboro. We’ll also test the control board and thermostat communication to ensure proper functionality.

6. System Age and General Wear

As heat pumps approach the 12- to 15-year mark, performance often declines—even if the system still runs. Older units struggle to maintain efficient heat transfer and may become costly to operate or repair.

Signs it’s time to consider replacement:

• • • Frequent breakdowns and service calls
    • Skyrocketing utility bills
    • Minimal heating output despite continuous operation
    • Outdated technology or low SEER/HSPF ratings

Solution:
Our team provides professional heat pump replacement services across Hillsboro, Tigard, Beaverton, and Lake Oswego. We’ll assess your current system, perform a proper load calculation, and recommend a high-efficiency model that’s sized and suited for your home.

Knowing what’s causing your heat pump to underperform is the first step toward restoring comfort. Whether it’s a minor issue or a sign that your system is nearing the end of its lifespan, Aviator Heating & Cooling is here to help with expert diagnostics, repairs, and long-term HVAC solutions.

Why Timely Repairs Matter

When your heat pump is running but not heating properly, it’s not just a comfort issue—it’s a signal that something within the system isn’t working as it should. Even if the system is still producing some heat, letting a small issue go unresolved can lead to bigger problems down the road.

An inefficient or malfunctioning heat pump creates a ripple effect throughout your HVAC system, increasing wear and reducing reliability. Here’s what can happen if you delay repairs:

• • Higher utility bills: A struggling heat pump works harder and runs longer to try to maintain your desired temperature, consuming significantly more energy in the process. Over time, this adds up on your monthly utility bill.
  • Premature system failure: When components like the blower motor, compressor, or reversing valve are forced to operate under stress, they wear out faster—shortening the life of your system and increasing the risk of total failure.
  • Inconsistent indoor temperatures: Rooms may feel too cold or too warm, with uneven heating that makes certain areas of your home uncomfortable or unusable.
  • Reduced indoor air quality: Restricted airflow, dirty coils, and clogged filters not only affect heating performance—they also contribute to poor air quality, which can aggravate allergies and respiratory issues.

By scheduling timely repairs, you protect your comfort, improve system efficiency, and avoid the inconvenience and expense of emergency breakdowns—especially during the coldest parts of the year when HVAC service demand is highest.

At Aviator Heating & Cooling, we provide prompt, professional heat pump diagnostics and repair services for homeowners across Hillsboro, Forest Grove, Tigard, Beaverton, and beyond. We take the time to pinpoint the exact cause of the problem, explain your options clearly, and perform expert repairs that restore your system’s performance. With our help, you can extend the life of your HVAC system, regain control over your comfort, and avoid being caught off guard when the temperatures drop.

Proudly Serving Hillsboro and the Surrounding Area

Aviator Heating & Cooling provides heat pump repair, replacement, and maintenance services throughout:

• • Hillsboro
  • Beaverton
  • Tigard
  • Aloha
  • Forest Grove
  • Lake Oswego
  • Sherwood
  • North Plains

No matter where you are in the region, our licensed technicians deliver prompt, professional service tailored to your home’s heating needs.

Still Cold? Let’s Get Your Heat Pump Working Again

If your heat pump is running but your home still feels cold, don’t wait for it to get worse. Call the trusted team at Aviator Heating & Cooling for expert diagnostics, fast repairs, and honest solutions. Whether you need a minor fix or a full system upgrade, we’ll help you stay warm and comfortable all winter long.

Contact us today to request an estimate or schedule service. We proudly serve homeowners in Hillsboro and the surrounding areas with dependable, high-quality HVAC solutions.